Ultralightweight meets extreme comfort.

 By Ryan Hansen

Sleep. Something I – and I’m willing to bet you, too – wish we had a lot more of. While some of us can deal with a lack of sleep – both in terms of quality and amount – I for one, struggle. Really, really struggle. If I’ve had a poor night’s sleep, never mind a bear with a sore head; no, I become the Grinch. Fortunately for my wife, Martine, the transformation only usually lasts a day. Usually. And it’s only sometimes that I steal people’s presents.  

Anyway, there’s very little that’s worse than being out in the middle of Woop Woop – or closer to civilisation, for that matter – after a long and intense day of whatever it is that you’ve been doing, and then having a shocker of a night’s sleep. And let it be known, since I’ve been sleeping on my new Nemo Tensor mattress, there’s barely been a Grinch in sight. 

Back in early July, I got my hands on the updated 2022 version of the Tensor, in the regular insulated option. (The Tensor comes in four different configurations – regular, regular wide, long wide, and regular mummy – all of which are available in insulated and non-insulated formats, thus catering to a variety of body sizes and personal preferences). I’ve spent 13 nights on mine, in a variety of conditions (from a sticky 10°C down to a chilly -2°C) and on a range of surfaces (from level and squishy, to uneven but firm, to hard and rocky), and I’ve been thoroughly impressed. On 11 of those nights, I slept warmly and comfortably (for the two outliers, I was a) sick and b) silly, I didn’t put enough air in it). 


In the field – or should I say, on the mountaintop – the first thing that struck me about the Tensor was the improvement insulation makes to comfort. Having previously exclusively slept on non-insulated mats, I was unaware of how much coolness from the ground, even on milder evenings, can affect your sleep – until, that is, the Tensor eliminated the cold almost entirely. Thanks to the two layers of reflective metallised film, which Nemo calls ‘Thermal Mirror’, and a (new for 2022) ultra-thin TPU layer within the baffle construction, the Tensor minimises convective heat loss for a snug and cosy siesta, with an R-Value of 4.2. Perhaps naively, I thought the insulation would be sweat-inducing on the warmer nights – granted, I haven’t yet used it in the peak of summer – but so far this hasn’t been the case. The other features which enhance its comfort include its ‘Spaceframe’ baffle design, which utilises low-stretch, die-cut trusses to reduce springiness, and its 8cm thickness – thicker than most others I’ve slept on.  


Given how suitable the Tensor is for pushing up Zs, it’s incredibly compact and lightweight. My regular insulated version weighs a mere 512g, (and can be lighter if you choose the mummy option) and steals less space than my 1L drink bottle. (For Martine and I, our two Tensors combined basically take up the same space that one of our old mattresses occupied, which was a standard non-insulated backpacking mat).

Other notable features of the Tensor include its Bluesign certified, recycled, 20D polyester fabric construction. The ‘Vortex’ pump sack is a bonus since, for other brands, such inflation sacks are an additional purchase; however, while it is designed to minimise mould build-up, I have already noticed internal moisture. The ‘Laylow’ valve also makes fine adjustments to air levels possible, although it can be a two-handed job (nuffys like me are likely to unintentionally deflate the whole mat by accidentally pulling the whole valve open when using one hand). At only 51cm, I’d also prefer a little extra width, but to me it’s a manageable sacrifice for its size and weight. This also applies to its thin construction, which means I much more thoroughly inspect the ground for sharp bits.

Overall, I like it. I like it a lot. And Martine loves it, since it’s done away with the Grinch.




Product Class:

Ultralightweight hiking sleeping mattress


Regular insulated


512g (including repair kit and ‘Vortex’ inflation sack)


183 x 51 x 8cm